Vehicle brake equalizer



March 26, 1940.

c. Z. SMITH VEHICLE ABRAKE EQUALIZER Filed Augf 2:5, 1957 '3 Sheets-Sheet 1" nell- 5 v Q hpv. 1 WN Q\ o LWN ng k\ N. M .ww/ uw Q March 26, 1940. C, z, sMlTH 2,195,099

VEHICLE BRAKE EQUALIZER Filed Aug. 2:5', 1957 s shuts-snm; 2

Marchas, 1940. 2.5mm 2,195,099

VEHIFCLE BRAKE EQUALIZER Filed Aug. 23.11937 s shuts-snm s :inventor CLARENCE'- Z SMITH 153 ttomegs Patented Mar. 2c, 1940 PATENT, OFFICE VEHICLE yBRAKE EQUALIZERl s Clarence Z. Smith, Atlanta, Ga.

Application August 23,

s claims. (o1. 18s-204.)l

Myinvention relates to lan equalizer for mechanical brakes of the two wheel, four wheelgor multiple type.

My invention is chiefly concerned with the development of; a ysimple and comparatively inexpensive mechanical equalizing transmission, compact in form, comprising elements operable by the ordinary hand and foot brake control means and adapted to vtranslate the applied power into a rformy that will .produce an equalized applica.-

` tion of brake pressure to each brake controlled wheel, which Ipower may be amplified Where it is desired to apply a greater pressure to one set of Wheels than to another set.

In its preferred embodiment, my invention contemplates thev provision of a transmission case in which an angularly and lineally movable primary actuator, constituting a floating power element, is adapted to equalize the motion imparted by it, Ieither directly to the brake actuators in the caseof va two wheel braking system, or indirectly through floating equalizers to the brake actuators of afour wheel braking system, so that the power available to operateA each brake will be equalized throughout the braking system.'

My invention further contemplates designing the primary actuator of the equalizer in the form of a double faced cam or wedge, preferably but not necessarily symmetrical in design, the `op`` posite sides of whichv engage and actuate the transmission elements which it controls.

My invention further contemplates designing the transmission case for a brake system of four or more Wheels soas to house therein not only the primary equalizing actuator but' also the sec# ondary oating equalizer transmission elements.

My invention also contemplates the interposition of roller bearings between the transmission elements and where needed as thrust bearings between thegtransmissionelements and the case, and to adapt'the case-.to house the equalizer elements so that they may Work in grease or lubricant. f' l My invention further contemplates causing the secondaryvactuators to cross to engage the primary actuatorv on opposite sides, and in` like manner for each pair of brake applying elements .f

to cross and engage opposite Working faces of their respective secondary actuator, with all the elements so mounted in the case that both the driving and driven actuators can oat in setting themselves to equalize the application of pressure to the several brake actuators.

My invention also comprises the novel details *'1937, serial No. 160,461

of construction and arrangements of parts which, in theiry preferred embodiment onlyare illustrated in the accompanying drawings which form a part of this specification, and in which:

Fig. 1 is a plan view Aillustrating a chassis with a four wheelibraking system showing one manner of connecting up the equalizerto the brake rods on the one han-d and to the brake applying elements onthe other. Fig. 2 is a plan view enlarged of the upper half of the equalizer casing inverted. Fig. 3 is a plan view of the lower half of the equalizer casing. 'f

Fig. 4 is a longitudinal lcross section through n the assembled casing taken on the line IV-IV of Fig. 3. s f

Fig. 5 is a transverse cross sectional view of the assembled transmission casing taken on the line V-V of Fig. 3.

Fig. 6 is a plan'view of one section `of an equalizer casing for a two` Wheel brake system embodying my present invention.

l Fig. 7 is a bottom view of the other section of the casing shown in Fig. 6. y

Fig. 8 is a detail View of an adapter applied to a brake crank to increase the leverage available to apply the brakes. i y

`Similar reference numerals refer to similar parts throughout the drawings.

j While it is to'be understood that my invention is applicable to varioustypes of brake systems for automobiles-or other vehicles., I have i11`us' trated it in its preferred embodiment in Figs.` 1 to 5 as applied to a four Wheel brake system for an automobile. L In Fig. 1 I have conventionally illustrated a chassis 9 Vwith front wheel brake drums I0 and rear wheel brakezdrums I I, and it will be understood that any form of brake mechanism may be utilized in the drums.r The brake mech'-v anism in each'dru'm is controlled by a crank arm or lever I2 tothe free outer end ofv which is attacheda brake operating rod which for the front wheels is indicated at I3 and for'the rear wheels is indicated at' I4. Any vsuitable type of transmitter may be used for applying the coupled to the front brake actuators 26 whichA shaft 20 by a4 rod 22 actuates a rocker shaft, not

shown, having crank connections to the brake rods I3, and I4. This mechanism is standard in most cars and is in part illustrated to show how my present invention may be coordinated with ythe 4present type of automobiles so as to be readily applied as an accessory thereto.

In applying my present invention to an existing four wheel mechanical brake system, the` sion casing 25. In like manner'the brake rods I f i3 for operating the front wheell brakes are enter the front side of the equalizer casing. Y

The equalizer casing 25, made in half sections vas shown more clearly in Figs. 2 and 3, houses a primary actuator having a shank `21 projecting forwardiy from the lcasing and connected to the pedal operated rod 22. A double faced wedgeor cam 2l is formed or otherwise mounted at the inner end of the shank '21. This shank where it enters and slides in the casing 25 is rounded to receive a felt packing 29 seated inthe contracted throat of a guide bearing 30 Which is flared (as will be more clearly seen in the device illustrated in Fig. 6) to permit the actuator to rock angularly in the casing. The `felt packing 29 will prevent at the point `of use the escape of grease With which the transmission casing should be kept filled. The doublefaced cam 28 of the primary actuator is thus mounted to fioat, free to have both angular motion in a horizontal plane `about bearing Sil, and lineal play in the equalizer casing, which is necessary to obtain equalization of braking pressure as ap- 1 plied vto the several brakes which it controls.

The outer iend of the shank `2 is provided with a hole 21a (Fig. 3) which is enlarged so that the pin, connecting `the shank to arrn'22, can have enough lateral play therein to allow the shank to have the limited vangular motionrequi-red Yfor it to equalize its action on the several brake'actuators which it controls.

" IThe casing 25 is so shaped as to receive secondary floating transmitters 3l `and 32, duplicates except that oneis a right hand and the other is a left hand element, which -passr one 'under and the other over` the primary actuator 2l. and are free to play as Vthey are moved responsive to the manipulation of the `primary actuator.

The underpassing transmitter 3l carries an upstanding stud` bearing pin 33 on Which is loosely set an antifriction roller 34 which engages the double cam 28.0n one side, Whilethe overpassing transmitter-32 is provided with `a depend-` ing stud bearing pin 35 upon which is loosely set an antifriction roller 36 which engages Vthe opposite side ofthe cam 28. f

The upper section of casing 25,v shown in Fig. `2, at or near its center receives an antifriction `roller 3l which is `mounted on afheadedstud bearing pin 38, threaded and screwed through the upper casing member and held fast by 4any suitable means. This roller 3l. serves' as a fixed roller4 thrust bearing against which the forward edgeof the overpassing transmitter 32 bears free to play angularly an-d yto have motion lineally without .frictional engagement withthe rvcasing whenactuated by the cam 28. 1

The under Asection of casing 25 is similarly equipped with an antifriction thrust bearing roller 40, similarly mounted on a stud bearing 4l against which the forward edgev of the underpassing transmitter 3| bears free to play lineally and angularly in the casing Without frictional engagement therewith, when actuated by the cam 28.

The rollers 3l and 4U function to prevent the inner ends of the transmitters rmoving forward in response to a 4forward pull on ,the cam 28 that is 4wedged between theirv rollersA 34 and 35, see Fig. 4, and they also form fulcrums about which the transmitters can rock horizontally as their outer ends shift in equalizing the action on the4 brakes they respectively control.

Each transmitter 3l, 32 is provided With a double faced cam orwedge42 and the casing 25 at each end is enlarged at 43 to receive these cams 42 with room forA them to play both lineally and angularly as, they perform `their work.

The actuators 25 forthe front wheelbrakes are rounded where they enter the forward sides of the chambers 43 `through guides 44`in which they are free only to slide, these guides being recessed at an intermediate point to receive felt packing rings 45 to prevent the escape of grease along the actuators. In like manner `the actuators 24 for the ,rear wheels enter Athe rear sides of these chambers 4B-through slide guides simi1arlypacked-`y 1 y Y It will be noted in Fig. 3 that each of these actuators has its inner iiattened end formed with a stop shoulder 46 to limit its outward movement from the casi-ng 25. front Wheel` actuator passes under the transmitter cam 42 which respectively controls it and is provided with an upturnedpin 41 upon which is ,loosely set an antifriction roller 48 which coacts with its respective double faced cam 42 on the side remote from the point where the actuator enters the casing l25. In like manner each overpassing actuator 24 for the rear brakes passes over its transmitter camy 42 and carries avdepending .pin 49 vupon which is loosely set an antifriction roller `D which rides on the casing bottom or any suitable slide support. y'Thus each secondary transmitter cam 42 is interposed betweenthe actuator members passing over and under-fit and engaged on opposite sides by the rollers'iiand 5D of said actuators.

The upper casing section (Fig. 2) carries at each end lan antifriction roller 5l mountedV on a fixed stud bearing `such .as 52 Vwhich isdisposed .to engagelthethrust bearing side edge of theoverpassingactuators 24, and in like manner the under portionv `of the casing carries rrsimilarly mountedrollers -53 adapted "to engage the thrust edges of the under .passing actuators. Asishownthe cam faces of allof the double-cams 42.and 28 terminate at their .innerends inconcav-e seats 54 conforming substantially to ,tl-re periphery of the rollers engaging such seats, thus providing a centering seat Minto which each actuator roller will come to rest when the brake applying pressure isreleased. l n i IheY-casing-sections are providedV with suitable apertured ears byA means of Ywhich theyf-are adapted to be -bolted vsecurely together with -a suitable gasketinterposed to -prevent the Vleakage of the contained lubricant, and the upperecasing section `isi-provided `with 1egs55-by means Aof which `it may be 4bolted' or M-othervvise attached toacross-support '56 ion-the fXf-frame.` 1"

It will of course be=understoodfthatthe brake mechanism for 4-eachf-Wheelf-is provided `with -suit- As illustrated, each when the brake applyingpressure is off and these lar disposition of the cam faces of the primary ao- I -springswill actv through thebrake rods;to pull vthe, actuatorsv 24 and 26 outwardly' until their stops 46 engage the transmission casing, when the rollers 48 and 150 on these 4actuators `will rest in the concave'seats 54 at thebases of'their respective wedge faces. In like manner the spring, (not shown) that resets thebrake pedal will thrust the primary actuator-cam-ZB inwardly I tothe position shown vin Fig. 3.with"thero1le`rs 34 and 36 on the secondary-transmitters resting in the seats 54 at the bases of their respective wedgefaces. The position of parts as shown in Fig. 3 is that assumed when the brakes-are relaxed. l

In operation, assuming the parts disposed in.

brake released position, as shown'in Fig. 3, when the brake pedal is operated, the primary actuator 2l is drawn forwardly from the casing and as' it moves it yforces its double wedge 28 between the rollers 34 and 3B which, bei-ng held against forward motion by the engagement lof the thrust bearing rollers 31 and 40, with the inner ends ofthe transmitters 3| and 32, will'be laterally displaced by the wedge 28 so as to have opposed lineal motion which will loe-equal and Without angular motion if no equalization action is required, but if the brake system controlled by either transmitter becomes set in ad- A Vance of that controlledy by the other, the cam l28 will shift angularly to continue fthe appli-` cation of braking pressure to theflatterv system until it too becomes set. In like manner, as each transmitter is actuated by' cam 28, if the two brakes it controls are equalized, it will have only linear motion; but if either of" its brakes sets4 in advance of the other its cam 42 will shift angularly until it sets both brakes equally. These transmitters are thus moved'reversely and as they move they arefree to play both angularlyland lineally .in a horizontal plane to allow for the equalization necessary for the. correct application. of the several brakes which they respectively control. As these floating transmitters are thus moved, their respective double cams'42 are drawn together and in-thus moving they wedge apart the rollers 48 and 50 carried by the brake actuators which they respectively control.' This results in thrusting or drawing .the brake actuators inwardly into the equalizer casingr and as they are thus drawn in they apply equalized pressure to operate the several brakes which they respectively control. Whichever brake sets rst, will arrest further movement of its respective roller and thus the further movement of the cam will bel exerted wholly to'displace the other transmitter or actuator which it controls and in Athis way equalization throughout is effected of the braking action on the wheels of the car. All transmission elements in the equalizer are free to iloat as they work and thoughthey are positively actuated they allow the4 braking system to set itself to its work with uniformity throughout. By this means a complete equalization of braking effect` is always provided for all of the brakes.

In order to obtain an equal motion for the angularly disposed brake actuators'24 and 26 as compared with that imparted to the aligning secondary transmitters 3| and 32, the angutuator 28 define between them an angle approxibrake which they respectively apply-'thus enabling an equalized power to be delivered to a selected group of brakes which however will producegreater orless eiect as compared with the brakes of another group. This allows more braking pressure to be applied to the rear wheels than tothe front wheels, or vice versa." In the'simpler embodiment of my invention designed for controlling a' single pair of wheel brakes. Here the primary actuator 62 and cam 63 are similar to 2l and 28 already described but the equalizer casing 6| is very much smaller than 25, as the secondary transmitters `3| and32 are omitted, and more'room for play is allowed'for actuator 62. vAn elongated hole 62a is provided in the outer end of the shank ofthe primary actuator 62 and serves the vsame purpose as that described for hole 21a in the shank-.21. The brake actuators 24 and 26 are also the same as already described and enter the 4transmission case through packed slide bearings and are shouldered at 46 to stop their outward play. -In the manner already described, one of them passes overand the other under the primary actuator 62 and the rollers 48 and 5,8 which they carry engage the opposite faces of the double actuator cam 63. lIn this arrangement, vwhen, the primary actuator or power cam 63 is moved, 'fit lwill exert directly on the brake actuators `an equalizing control similar to that alreadydescribed. This equalizer casing 6| is formedinv half` sections bolted together with an interposed gasket, like casing 25, and it has similar mounting legs 55.l Its sections also carry the thrust It is contemplated that the equalizer casings 25 and 6l will be packed with [grease and any convenient means may be used forv its replace'- ment.

My invention is characterized by the utiliza'A construction, the secondary transmitters are duplicate; forgings which differ merely in the position of the roller stud bearing pins and all four of the brake actuators are duplicate forgings yalso differing merely in the application of their i roller bearing pins.

While I have shown my invention in but two` forms, it will be obvious to those skilled in the invention,` which is illustrated in Figs. 6 and 7,' I showmy .bearing rollers 31 and '40 for the brake actuators.

art that itis not so limited, but is susceptible of various other changes and modifications, without departing from theyspirit thereof, and I desire, therefore, that only such limitations shall be placed thereupon as are imposed by the prior art` or as are specifically set forth in the appendedvr claims.

What I claim is: i

1. A mechanical equalizer means for vehicle brakes, comprising a wedge actuator mounted free for angular and lineal motions, brake actuators mounted for lineal movement, thrust bearings to hold said brake actuators substantially to linear movement, and rollers journalled on the brake actuators and disposed to engage the Wedge actuator between them in position to produce equalized lineal motion in the brake actuators responsive to lineal movement of the actuator.

2. A mechanical equalizer meansfor Vehicle brakes, comprising a wedge actuator mounted free for angular and lineal motions responsive to pedal control, brake actuators mounted for lineal play, thrust bearings for saidk brake actuators disposed to prevent their angular play responsive to thrust imposed thereon by the wedge actuator,

and rollers journalled, on the brake actuators and disposed to engagethe wedge actuator between them in position to produce equalized lineal motion in the brake actuators towards the actuator responsive to lineal movement of the actuator.

3. A mechanical equalizer according to claim l, in which the brake actuators cross over and under said wedge actuator, and a casing which is filled with lubricant, encloses and acts to hold said brake actuators in engagement with said wedge actuator.

4. A mechanical equalizer means for vehicle brakes, comprising a casing, a primary pedal actuated wedge mounted for reciprocation and lateral play in said casing, secondary transmitters crossing the wedge from opposite sides and having elements that engage the wedge between them, thrust bearings for the transmitters, a

wedge on each transmitter, and brake actuators mounted to reciprocate on said casing, responsive to movement of said transmitter wedges.

5. A mechanical equalizer for Vehicle brakes,

. comprising a pedal reciprocated double Vfaced wedge mounted free for lateral play, transmitters c rossing said wedge with rollers engaging the wedge between them, thrust bearings rfor the transmitters leaving them free for lineal and angular play, a double wedge carried by each transmitter, a'pa'ir o f ,brake actuators for each transmitter carrying rollers mounted to engage their respective ytransmitter `wedge between them, and

cable wedge mounted for angular and lineal play,

driven elements mounted to pass, one over and the other under, thev wedge from opposite sides thereof, rollers on one end of each of said elements which engage the wedge between them, thrust bearings for said elements, and means connecting said elements to the brakes they respectively operate, said means each comprising like groups of elements consisting of a floating wedge actuator, crossed elements carrying rollers engaging their respective wedge actuator between them, thrust bearings for said latter elements,

and a brake rod connecting each latter element f to the brake it respectively controls;

8.*In a mechanical equalizer, a sectional casing containing lubricant and brake actuators slidable thereinto, a pedal actuated double faced wedge slidable into and free for lateral play in said casing, crossed transmitters passing over and under said wedge and carrying on their inner ends rollers that engage the wedge faces between them, a` wedge head on each transmitter, a pair of said brake actuators being crossed relatively to each wedge head and equipped with rollers that engage the wedge Yhead between them, and means to seal the joints between the casing sections and surrounding each brake actuator and the pedal actuated wedge.

CLARENCE ZY. SMITH. 

